The Cardinal fish is a mouth brooder, with the males holding the freshly fertilized eggs in their mouth until they are ready to hatch. The males are unable to eat during this time frame, but sometime sneak a few eggs from the brood to tide them over. If you are patient, they rotate, clean and aerate the eggs in their mouth every 3-5 minutes, giving a quick glimpse of the eggs!
A male clownfish cleaning fertilized eggs. Each family of clownfish has a single reproducing female that lays eggs for the largest male to fertilize. If the female is killed or dies, the largest male will transition into a female taking her place, with the next largest male stepping into to fill his role.